The evolution of parasitism in Nematoda.
The evolution of parasitism in Nematoda.
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DOI：
10.1017/s0031182014000791
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发表时间：
2015-02
期刊：
影响因子：
2.4
通讯作者：
Koutsovoulos G
中科院分区：
文献类型：
--
作者：
Blaxter M;Koutsovoulos G
线虫种类繁多，种类繁多，包括许多寄生物种。分子系统发育分析表明，植物和动物的寄生至少独立出现了15次。现存的线虫物种也表现出被认为处于寄生进化轨道上的生活方式。最近的进展使许多线虫物种的基因组和转录本的测定成为可能。这些新数据可以用来进一步了解线虫的系统发育，并识别与寄生有关的可能的遗传模式。植物-寄生线虫基因组显示了来自根际其他成员的水平基因转移，这些基因在寄生-寄主界面中发挥着重要作用。类似的水平转移在动物寄生虫群中并不明显。许多线虫都有细菌共生体，这可能是生存所必需的。从共生体向线虫的水平转移也很常见，但其生物学意义尚不清楚。目前有100多种线虫物种被作为测序的目标，这些数据将对寄生的生物学和进化史产生重要的见解。重要的是，这些新技术也应用于自由生活的类群，这样就可以推断寄生前的基态，并隔离与寄生相关的新奇事物。
Nematodes are abundant and diverse, and include many parasitic species. Molecular phylogenetic analyses have shown that parasitism of plants and animals has arisen at least 15 times independently. Extant nematode species also display lifestyles that are proposed to be on the evolutionary trajectory to parasitism. Recent advances have permitted the determination of the genomes and transcriptomes of many nematode species. These new data can be used to further resolve the phylogeny of Nematoda, and identify possible genetic patterns associated with parasitism. Plant-parasitic nematode genomes show evidence of horizontal gene transfer from other members of the rhizosphere, and these genes play important roles in the parasite-host interface. Similar horizontal transfer is not evident in animal parasitic groups. Many nematodes have bacterial symbionts that can be essential for survival. Horizontal transfer from symbionts to the nematode is also common, but its biological importance is unclear. Over 100 nematode species are currently targeted for sequencing, and these data will yield important insights into the biology and evolutionary history of parasitism. It is important that these new technologies are also applied to free-living taxa, so that the pre-parasitic ground state can be inferred, and the novelties associated with parasitism isolated.